Merge pull request #1397 from caolan/linked-list-methods

queue.remove()

lib/internal/DoublyLinkedList.js

@@ -23,7 +23,10 @@ DLL.prototype.removeLink = function(node) {
     return node;
 }
 
-DLL.prototype.empty = DLL;
+DLL.prototype.empty = function () {
+    while(this.head) this.shift();
+    return this;
+};
 
 DLL.prototype.insertAfter = function(node, newNode) {
     newNode.prev = node;
@@ -60,3 +63,26 @@ DLL.prototype.shift = function() {
 DLL.prototype.pop = function() {
     return this.tail && this.removeLink(this.tail);
 };
+
+DLL.prototype.toArray = function () {
+    var arr = Array(this.length);
+    var idx = 0;
+    var curr = this.head;
+    for(idx = 0; idx < this.length; idx++) {
+        arr[idx] = curr.data;
+        curr = curr.next;
+    }
+    return arr;
+}
+
+DLL.prototype.remove = function (testFn) {
+    var curr = this.head;
+    while(!!curr) {
+        var next = curr.next;
+        if (testFn(curr)) {
+            this.removeLink(curr);
+        }
+        curr = next;
+    }
+    return this;
+}

lib/internal/queue.js

@@ -101,6 +101,9 @@ export default function queue(worker, concurrency, payload) {
         unshift: function (data, callback) {
             _insert(data, true, callback);
         },
+        remove: function (testFn) {
+            q._tasks.remove(testFn);
+        },
         process: function () {
             // Avoid trying to start too many processing operations. This can occur
             // when callbacks resolve synchronously (#1267).

lib/queue.js

@@ -24,6 +24,12 @@ import wrapAsync from './internal/wrapAsync';
  * task in the list. Invoke with `queue.push(task, [callback])`,
  * @property {Function} unshift - add a new task to the front of the `queue`.
  * Invoke with `queue.unshift(task, [callback])`.
+ * @property {Function} remove - remove items from the queue that match a test
+ * function.  The test function will be passed an object with a `data` property,
+ * and a `priority` property, if this is a
+ * [priorityQueue]{@link module:ControlFlow.priorityQueue} object.
+ * Invoked with `queue.remove(testFn)`, where `testFn` is of the form
+ * `function ({data, priority}) {}` and returns a Boolean.
  * @property {Function} saturated - a callback that is called when the number of
  * running workers hits the `concurrency` limit, and further tasks will be
  * queued.

mocha_test/linked_list.js

@@ -0,0 +1,83 @@
+var DLL = require('../lib/internal/DoublyLinkedList').default;
+var expect = require('chai').expect;
+
+describe('DoublyLinkedList', function () {
+    it('toArray', function() {
+        var list = new DLL();
+        expect(list.toArray()).to.eql([]);
+
+        for (var i = 0; i < 5; i++) {
+            list.push({data: i});
+        }
+        expect(list.toArray()).to.eql([0, 1, 2, 3, 4]);
+    });
+
+    it('remove', function() {
+        var list = new DLL();
+
+        for (var i = 0; i < 5; i++) {
+            list.push({data: i});
+        }
+
+        list.remove(function (node) {
+            return node.data === 3;
+        })
+
+        expect(list.toArray()).to.eql([0, 1, 2, 4]);
+    });
+
+    it('remove (head)', function() {
+        var list = new DLL();
+
+        for (var i = 0; i < 5; i++) {
+            list.push({data: i});
+        }
+
+        list.remove(function (node) {
+            return node.data === 0;
+        })
+
+        expect(list.toArray()).to.eql([1, 2, 3, 4]);
+    });
+
+    it('remove (tail)', function() {
+        var list = new DLL();
+
+        for (var i = 0; i < 5; i++) {
+            list.push({data: i});
+        }
+
+        list.remove(function (node) {
+            return node.data === 4;
+        })
+
+        expect(list.toArray()).to.eql([0, 1, 2, 3]);
+    });
+
+    it('remove (all)', function() {
+        var list = new DLL();
+
+        for (var i = 0; i < 5; i++) {
+            list.push({data: i});
+        }
+
+        list.remove(function (node) {
+            return node.data < 5;
+        })
+
+        expect(list.toArray()).to.eql([]);
+    });
+
+    it('empty', function() {
+        var list = new DLL();
+
+        for (var i = 0; i < 5; i++) {
+            list.push({data: i});
+        }
+
+        var empty = list.empty();
+
+        expect(list).to.equal(empty);
+        expect(list.toArray()).to.eql([]);
+    });
+});

mocha_test/queue.js

@@ -761,5 +761,24 @@ describe('queue', function(){
             q.push('foo4', function () {calls.push('foo4 cb');});
         });
     });
+
+    it('remove', function(done) {
+        var result = [];
+        var q = async.queue(function(data, cb) {
+            result.push(data);
+            async.setImmediate(cb);
+        });
+
+        q.push([1, 2, 3, 4, 5]);
+
+        q.remove(function (node) {
+            return node.data === 3;
+        });
+
+        q.drain = function () {
+            expect(result).to.eql([1, 2, 4, 5]);
+            done();
+        }
+    });
 });